The invention relates to the field of computer aided design (CAD). More specifically, the invention relates to generating and displaying cutout features in a three-dimensional solid geometry piece.
Computer aided design (CAD) programs have allowed users to design various parts in xe2x80x9cvirtualxe2x80x9d space before the parts ever reach a manufacturing stage. As CAD programs have become more powerful, parts modeled in xe2x80x9cvirtualxe2x80x9d space (i.e., CAD models) have become more true to life. Often times, these CAD models are also referred to as three-dimensional (3-D) solid models or as solid models because of the fact that they are 3-D geometry pieces with solid properties, such as volume, faces that define the boundary of the three-dimensional solid geometry piece, weight, and so forth. Because the 3-D solid geometry pieces have solid properties, solid operations, such as cutting holes, joining other models, and so forth, are performed on these models. For example, a user may design a 3-D solid geometry piece of a plate, and often times, the plate may have varying surface areas, such as one or more bend areas. Additionally, the user may desire a cutout feature in the plate, and the cutout feature may cut through the one or more bend areas increasing the complexity of the design.
In order to generate a cutout feature in a 3-D solid geometry piece, such as a plate, under the prior art, the user sketches a two-dimensional (2-D) geometry piece of the shape of the cutout feature. A solid operation is performed on the 2-D geometry piece to form a 3-D solid geometry piece of the cutout feature. If the cutout feature cuts through a flat area of the plate, a subtraction operation is performed between the 3-D solid geometry piece of the cutout feature and the plate, thereby generating a cutout hole through the plate. However, if the cutout feature is through a bend area of the plate, in order to form the 3-D solid geometry piece of the cutout feature through the bend area, the user may be required to perform a series of complex operations.
One series of complex operations may involve flattening the plate to remove the bend area, forming a 3-D solid geometry piece of the cutout feature, performing the subtraction operation, as described above, and then, bending the plate back to it original shape with the bend area. Only at this time, will the user be able to visualize the cutout hole through the bend area.
Another series of complex operations may involve forming a 3-D solid geometry piece of the cutout feature, bending the 3-D solid geometry piece of the cutout feature, and then, performing the subtraction operation, as described above, between the plate and the 3-D solid geometry piece of the cutout feature. Again, once the subtraction operation is performed, the user can visualize the cutout hole through the bend area. Bending the 3-D solid geometry piece of the cutout feature to match the bend areas of the plate may be difficult.
After multiple operations to at least visualize the cutout hole, if the user is not satisfied with the cutout hole, the user is required to perform undo operations on the series of operations performed to get back to the original 3-D solid geometry piece of the plate without the cutout hole. The series of undo operations may involve extensive calculations for the CAD program. Additionally, forming a 3-D solid geometry piece of the cutout feature causes extensive calculations for the CAD program, and file sizes of data associated with 3-D solid geometry piece are large.